Hypersensitivity pneumonitis: Clinical manifestations – Prospective data from the interstitial lung disease-India registry

Abstract

Context:Multiple environmental factors are associated with development of hypersensitivity pneumonitis (HP), and diagnostic algorithms for the diagnosis of HP have been proposed in recent perspectives.Aims:We analyzed the data of patients with HP from interstitial lung disease (ILD)-India registry. The analysis was performed to (1) find the prevalence of HP, (2) reclassify HP as per a recently proposed classification criterion to assess the level of diagnostic certainty, and (3) identify the causative agents for HP.Setting and Designs:This was a prospective multicenter study of consecutive, consenting adult patients with new-onset ILD from 27 centers across India (March 2012–April 2015).Materials and Methods:The diagnoses were based on prespecified working clinical criteria and multidisciplinary discussions. To assess strength of diagnosis based on available clinical information, patients with HP were subclassified into definite HP, HP with high level of confidence, and HP with low level of confidence using a recent classification scheme.Results:Five hundred and thirteen of 1084 patients with new-onset ILD were clinically diagnosed with HP and subclassified as HP with high level of confidence (380, 74.1%), HP with low level of confidence (106, 20.7%), and definite HP (27, 5.3%). Exposures among patients with HP were birds (odds ratios [OR]: 3.52, P < 0.001), air-conditioners (OR: 2.23, P < 0.001), molds (OR: 1.79, P < 0.001), rural residence (OR: 1.64, P < 0.05), and air-coolers (OR: 1.45, P < 0.05).Conclusions:About 47.3% of patients with new-onset ILD in India were diagnosed with HP, the majority of whom were diagnosed as HP with a high level of confidence. The most common exposures were birds, cooling devices, and visible molds.

Bagassosis, rare cause of hypersensitivity pneumonitis: A case report

“…HP is a rare entity except in certain professions, as an example the prevalence of farmer's lung was found to be 4.2/1000 farmers [4]. In India HP was found to be the most common type of ILD diagnosed in 47.3% of patients in the ILD-India registry [5]. Bagassosis is a rare cause of HP caused by significant exposure to bagasse.…”

The increasing trend and the seasonal variation in attendance of diffuse parenchymal lung disease patients presenting to a pulmonary clinic in Eastern India

“…For hypersensitivity pneumonitis, the major etiology of DPLD in ILD-India registry, the risk has been increased in users of forced air heating or air conditioning through the use of air coolers and air conditioners. [ 15 ] There has been an increased odd for the user of air coolers and air conditioners in a multivariate analysis in the development of HP in India; the odds ratios 2.23 ( P < 0.001), and 1.45, ( P < 0.05) for has been conditioners and air-coolers, respectively[ 16 ] Forced air heating or air-conditioning systems were detected to result in HP as early as 1976. [ 17 ] The use of air coolers and conditioners are mostly done in the summer months that correspond to the peak in May, the hottest month across the country.…”

High-Resolution Computed Tomography of Fibrotic Interstitial Lung Disease

“…In up to 60% of cases, no inciting antigen is identified, 126 127 128 129 130 contributing to a widely varying registry prevalence of HP (2–47%) among patients with ILD. 131 132 133 134 135 136 137 138 139 140 141 There is also overlap between the presentation of HP and other fibrotic ILDs, leading to misdiagnosis and delayed management. 142 143 144 145 146 Although previously categorized based on symptom duration at the time of presentation (i.e., acute, subacute, or chronic), 147 148 inconsistency is reported in the outcomes of these subgroups; the natural history may include anything from progressive improvement to respiratory failure and over half of HP patients present with fibrosis.…”